Piston.



No. 057,000. f Patented sept. u, |000. w. HEsToN.

PISTUN.

(Application led Oct, 9, 1899.)

(No Model.)

v TH: 'mums Pmns cc.. wfomumo.. wwfmn'ron. n. c.

UNITED STATES 'PATENT OFFICE..

wILLIAM HEsroN, or HOMESTEAD',` PENNSYLVANIA.

PlsroN.

SPECIFICATION forming part of Letters Patent o. 657,600, dated September 11, 1900. Application led October 9, 1899. Serial No. 733,001. (No model.)

T0 @ZZ whom it may concern/1,:` f p Beit known that I, WILLIAM HnsToN, a citizen of the United States, residing at Homestead, in the county of Allegheny and State of Pen nsylvania, have invented a certain new and useful Improvement in Pistons, ofgwhich thefollowing is a full, clear, and exact description, reference being had to the accompanying drawings. A

The object of this invention is to provid novel means whereby the packing-rings of a piston may be expanded Without necessarily removing-the piston from its cylinder. invention is especially valuable when applied to hydraulic piston-valves, and it is so shown in the drawings, but it is applicable to and of greater or less value with any kind of a piston.

The invention consists in the combinations hereinafter described, and pointed out deflnitely in the claims.

In the drawings, Figure 1 is a central longitudinal section of my improved piston and` its cylinder; and Fig. 2 is a horizontal sectional view on line 2=2 of Fig. l.

vIn the construction shown the invention is applied to the piston oni both'sides of the central head, whereby the piston is better adapted-for that use for which this" particular embodiment of the invention is organized--viz., as a balanced hydraulic piston-valve. 'Obviously, however, this is mere duplication and unnecessary, and therefore the description of the combination of parts constituting the invention, shown in the drawings above the central head, will be found to apply to the combination of parts below said head. Referring to the parts by letters, A represents the cylinder, inwhichthe piston is movable. The inlet port or pipe is designated G. The pipes leading to and from the machinery to be operated are G' and the exhaust pipes from the valve G2. The piston-body shown consists of a head b, having an annu` lar recess about it and a tubular stem b', ex-` A tending from it, and isshiftable by the racked yoke J, which meshes with the operating-segment H. At either extreme operative position of the piston, which in the drawings is either side of the @entera distance about equal to the distance across the annular recess in the head, `the annular recesscouples one of the pipes G from the machinery with the corresponding exhaustp ipe G2, wllile the other pipe G2. is closed and the pipe G to the machinery is coupled with the pipe G around the endof the piston. The head b will lit the cylinder as nearly as desirable or practicable, and the stem b' will be extended out through a stuing-box d in the end of the cylinder. l f y b2 is an adjustable collar which is screwed onto the stem. The packing-rings C, which embrace the stem, are held between this co1- lar b2 and the head b. These rings may be Vmade of any suitable material and have any suitable construction, provided they are capable of expansion by substantially the means provided. I preferto make themof leather. Ihese rings do not come into direct contact with the-stem, but do embrace a tapered sleeve D, which in turn embraces and is movable upon the stem. In the proximate face of the head b and collar b2 are the annular recesses b3 b4, respectively, into which the ends of said sleeve may project, and these `recesses are deep enough to permit as much endwise movement of the sleeve as is desirable.

In the tubular stem b' a longitudinallymovable rod E is tted, its outerend projecting beyond the end of said'stem. The projecting outer end is threaded for the reception voi" the nut F, which bears against the end ofV the stem. Atwthe `inner end of this rod are the laterally-projecting fingers e e,

which extend thro ugh longitudinal slots b5 in the stem b' and engage with the tapered sleeve D\, entering the `notches d in the large end thereof. Nowjwhen it is `desiredto expand the packing-rngsC to take up wear or for any other reason the rod E `is drawnoutward by screwing the nut F against the end of the stem b', and this movement of `said rodis transmitted by the jingersM eto the tapered sleeve D, which is thereby moved endwise toward its small end.A The packing-rings are prevented from endwise movement by the collar `b2,and they are therefore expanded proportionately to the `movement of said sleeveD.

Having described my invention, I iniml.` The combination of a piston-head, a tubularfstem extending therefrom, a tapered IOO l sleeve slidably inounted upon saidstern, al rodHV v `within the stem,'apro`jection on said rods-ex tending through a slot in the stern into en-l l gagement with-said sleeve, expansiblepackf-,

ing-rings aroundthe sleeve adapted to. be

"pressed outward thereby, and a follower in Lthreaded engagement with Vthe -stefm l and' adaptedito press said packing-rings toward 'vIo the piston-head, therelbeing provided an auf; nular recess about the stem on the operative 'Y side of said follower into which the end ofthe vtapered sleeve..maytakeysubstantiallyasidescribed. f v

2. The combination of` av piston-head hav-'- ing an annular recesson one side, a tubular stein extending from said head, a' tapered Y sleeve' slidably mounted upon said stem 'and adapted to occupy said recess, a rod within "said'stem`,a cross-keyon said-rod extending through slots in the stern and taking into openings in said sleeve, expansible packing- `rings surrounding said sleeve and adapted to be expanded thereby, and a follower in threaded engagement withthe sleeve and having a 'projecting ange bearing' againstsaid packi n,g'rings whereby the follower may compress 'the packing-rings Abetween it and the piston 'while leaving an.annular recess about the i stem vinto which said tapered sleeve maytake, substantially as described.

In testimony whereof I hereunto allx my Vsignature in the presence of two witnesses.

Y v WILLIAM HESTON.

Witnessesi` ALBERT` H. BATES', E. L. THURsCroN.V 

